Collapsible core for concrete piles.



.i. m. UPSON H. R, SMETH. coLLAPssBLE comi ma CONCRETE mss.

APPLICATION FILED AUG. 4, i914.

Patened Sept. 26,

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MeXWELL M. Ursem, or ENennworm,l una?.

renin n. Y., nsseivons 'ro nsrivrotn JERSEY, AND HERIVAN R.. SMITH, DE lllllll'l CONCRETE PILE COMPANY, OF Nllf 'IRK,

N. Y., A. CORPORATION OF NEW JERSEY.

COLLAPSIBLT ORE FOR CONCRET PILES.

grinsen-mw ,ccetion of Letters atent.

inserire.

)Patented Sept., 2d,

Application led August 14, 1914. Serial No. 856,801.

To all whom it may concern Be it known that we, MAXWELL M. UrsemT and HERMAN R. SMITH, citizens of the United States, residing, respectively, at'

Englewood, county of Bergen, and State of New Jersey, and New York, county and State of New York, have invented certain new and useful Improvements in Collapsible Cores for Concretel Piles, of which the foli-t lowing is a full, clear, and exact description.

As is well understood, Concrete piles are .formed by driving into the ground a thin sheet metal or papier mche shell, usually closed at its lower end, filling the shell with plastic concrete, and .allowing the same to set. The shell is usually driven by a collapsible form or core, which when expanded iits its interior, and after driving is collapsed to a less diameter, so as to be easily removable from the shell. 011e type of such collapsible core is shown in patent to Raymond, No. 777,351 in which the core comprises an inner member and a plurality of outer sections, both inner and outer members being provided with inclined engaging surfaces, which when fully engaged, expand the core to its full diameter, and'when disengaged-by pulling the inner member upward-permit the outer sections to be collapsed inwardly, out of Contact with the pile shell and so to be withdrawn from the shell.

Considirable diliiculty has been experienced in properly proportioning the angle of inclination of the engaging surfaces. If the taper is rather sharp, say l to Il, the friction to be overcome in the upward, or collapsing pull on the inner member, is small, so that the collapsing is easily aceomplished, even where there is an accumulation of dirt and water on the engaging surfaces, as is not uncommon in practice.

But with this taper, about 25 per cent. of

the inward thrust in drivinff-due to the resistance or pressure of the earth on the outside of the shell-acts in a vertical direction upon the inner member because of the angle of inclination; and this is substantially equal to thev friction of the engaging surfaces; so that it has been found in driving into certain earths that the inner member will tend to rise with reference to the outer members between blows of the driving ham mer; consequently the mechanism upon the inner member which serves to hold the outer member in expanded position comes into contact with the outer member and the vibration or elastic rebound of the inner-4 member caused by the blows of the hammer is very destructive of the holding mechanism. In order to overcome this ditliculty, the angle of inclination of the wedging meer bers has been materially lessened; thereby the upward thrust on the inner member is decreased and is less than the friction between the engaging surfaces. The excess of friction over upward thrust serves to hold the inner member in fully lexpanded po sition` preventing the tendency of the inner member to rise, and eliminates the destructive effects of vibration and contact between holding mechanism and outer member.

However, because of the excess of friction.

atthc engaging surfaces, it is much more ditlicult to pull the engaging surfaces apart in order to collapse lthe core. n some cases where the earth friction is great apen the exterior of the pile shell, it has been impossible to pull up the core; while in others, as in quiclrsand, where the earth friction is small, the pile shell has pulled out with the core, thereby defeating the ultimate purpose of the device. lt is to overcome these and other objections that our present invention is designed.

. In the drawings: Figure 1. represents in longitudinal section my improved. collapsible coro. Figs. 2 and 3 `,are details of the upper part in expanded and collapsed positions, respectively. Fig 4 is section on the line 4--4 of Fig. l.

Uur pile/core is formedwith an inner member, l, which consists essentially of a rod or pipe of sufficient length to extend through the entire pile casing, and of suihcient strength to meet the requirements of this service. This inner member is provided, at suitable intervals throughout its length, with a series of wedge-faces 2, preferably formed on circumferential ribs or rings, and which are arranged to contact with similar, but inwardly projecting, wedge members, or inclined faces, 3, on the outer sections of the collapsible core. The inner member and the' outer sections 4 may be attached together,` as bythe links 5 placed et intervals throughout their length, so'that, after coln'iembcr is provided with a head, (i, which is also attached to the outer sections 4 by links /5. Seated in a recess in head 6 is a second, or false head 7, which is connected with thelower head 6 by a series of latches 8 en- 10 gagging with suitable lugs therein. The

lower head (i is provided with a recess 9 into which projects a rod or shaft 10, having vertical movement in the recess, and permanently attached t the upper head 7. The

` lower head 6 is also provided with a series of lateral recesses 11, in each of which is mounted a rocking lever 12, so formed and arranged as to be normally in contact with one of the outer core-members 4, or a lug or inward extension thereof 13. Each lever 12 also has a head or projection 14, projecting into a recess 15 in the rod or shaft 10; so that when the upper head is raised, as by pulling on the ropes 16 (after releasing the latches 8), the heads 14 on the rocking levers 12 will be raised'and the rear sides pressed downward against the lugs 13 and outer members 4. The levers 12 are mounted on pins 12 affixed to the lower heads 6, and

by suitably proportioning., arranging and mounting the levers, the force of the pull upward upon the upper head 7 and shaft or rod 10 may be transmitted in any desired ratio of increase (within rather wide limits) into pressure downward upon the outer core members of sections 4. We have found a fratio of 1 to 6 to be suitable for our purpose. When the parts are arranged as shown in Figs. 1 and 2, the core is ready to be inserted in the pile-shell for dri-ving the latter into position in the earth, in the usual manner. After this operation is completed, the latches 8 are released from the lugs in the lower head, and the ears 16 are connected With the blocks or other means used to withdraw the core. As soon as the pulling force is exerted, the upper head 7 slightly raised and with it the rod or shaft 10, thereby, through the .50 levers 12 exerting downward pressure upon the outer sections 4, until the pull upon the upper members rocks the lever-heads 14 upward, at the same time raising the lower head t3 and inner member 1 until the wedges 2 are raised out of engagement with the wedges when the outer core members 4 will collapse inwardly, out of engagement with the pile shell, and therefore the entire core may be readily withdrawn from the no pile-shell.

The angle of inclination of the. wedging surfaces, 2, 3, may be varied considerably, `ilthough we prefer to flatten it only to the extent necessary to overcome the tendency of the inner member to rise.

The latches 8 may be provided with springs 8, tending to throw them into engagement with the lugs on lower head (i.

Manifestly our invention is susceptible of considerable variation; for example other well known mechanical substitutes may be employed in place of the levers for effecting their functions, so that the description and drawings are to be understood typical and not limiting.

1. In a. collapsible core for pile shells, the con'ioination of an inner expanding member and an outer expansible member each provided with inclined contacting surfaces, levers mounted on the inner member and normally in contact with the outer member and so arrangedI that an upward pull on the inner member multiplies the power ot the pull and exerts it in a-downward direction upon the ou`ter member.

2. In a collapsible core for pile shells, the combination of an inner member and an outer member each provided with a con tacting surface and means interposed between said members and arranged to transmit an upward pull on one member into a downward thrust upon the other member.

3. ,ln a collapsible core for pile shells, the combination of an inner member and an outer member each provided with contac-ting,r surfaces and rreans interposed between said members adapted to transmit force applied in one direction into oppositely directed thrust upon the other member respectively.`

4. In a collapsible core for pile shells, tho combination of an inner member and an outer member each provided with one or more inclined engaging' surfaces, a twopart head upon thefinner member, one part of which head has sliding engagement with the other part, a lever mounted uponsaid head and havinnr one end in the path of movement of said sliding part, and its rear end in engagement with said outer member.

5. ln a collapsible core for pile shells, the combination of an inner member and an outer member each provided with one.

or more inclined engaging surfaces, a twopart head upon the inner member, one part of which has slidingengagement with the other part, and a series of levers mounted upon .said head each having,r one end in the path o n'iovement of said sliding part and its rear end in engagement with said outer member.

6. In a collapsible core for pile shells, the combination of an inner member and an outer member each provided with one or more inclined engaging surfaces, a twopart head upon the inner member, one part of which head has sliding engagement with the other part, and a series of levers upon said head, each having one end in the path of movement of said sliding part, and its rear endin engagement with one vof said outer members.

7. A head for collapsible cores comprising a lower member provided with rocking levers, an upper member having sliding engagement with said lower member, means upon the upper memberfor operating said levers, said levers being so constructed and arranged'as to multipl57 the-force of an upward pull exerted upon the upper member and transmute it into a downward thrust at their outer ends, substantially as 'and forattached to said. upper member and sliding,y fin said aperture, a series of levers 12 mount-'"1' jing relation to each other, substantially as and for the purposes described.

In testimony whereof we aix our signatures in the presenceof two subscribing witnesses. f 1

MAXWELL M. UPSON. HERMAN R. SMITH.

`Witnessesz THOMAS J. BYRNE, WILLIAM P. JOHNSON. 

